1. Field of the Invention
The present invention relates to an inverted pendulum type vehicle.
2. Description of the Related Art
There has conventionally been known an inverted pendulum type vehicle in which a rider mounting section, which is tiltable with respect to a vertical direction, is installed to a base body to which a traveling unit capable of traveling on a floor surface in all directions and an electric motor that drives the traveling unit are installed. The inverted pendulum vehicles of this type are described in, for example, Japanese Patent Application Laid-Open No. 2012-126257 (hereinafter referred to as Patent Document 1) and PCT International Publication No. WO2011/033580 (hereinafter referred to as Patent Document 2)).
In this type of an inverted pendulum type vehicle, the operation of the electric motor is controlled to control the travel of the traveling unit, thereby controlling the posture, i.e. the tilting state, of the rider mounting section.
The total mass of an inverted pendulum type vehicle (hereinafter referred to simply as “the vehicle” in some cases) differs between a state in which a rider is on the vehicle (hereinafter referred to as “the occupied state” in some cases) and a state in which a rider is not on the vehicle (hereinafter referred to as “the unoccupied” in some cases). Thus, a reaction force acting on the inverted pendulum type vehicle from a floor surface differs. Hence, the behavior characteristics of the vehicle differ depending on whether the vehicle is occupied or unoccupied.
Therefore, Patent Document 2 mentioned above proposes a technique in which a load sensor provided in a rider mounting section is used to detect whether the vehicle is occupied or unoccupied, and a gain value for feedback control is adjusted according to a result of the detection.
However, depending on how the rider rides on the vehicle, the rider does not always ride on the rider mounting section such that his or her weight is applied to the load sensor. Further, depending on the mounting position or mounting posture of the rider relative to the vehicle, there are cases where the load of the weight of the rider is not sufficiently applied to the load sensor. In such a case, the occupied state may be erroneously determined as the unoccupied state.
If such an erroneous determination is made, then the travel control will be inconveniently carried out on the traveling unit in a manner corresponding to the unoccupied state whereas the vehicle is actually occupied.
Patent Document 1 does not describe a technique fir properly detecting whether or not a rider is on the vehicle.